Piston



(No Model.)

Y Y 2 sheets-sheet 1. W. R'O-WAN.

PISTON.

Patented Jan; ZZ, 1884.

'WILLIAM Rowan, or BELFAST,

'PATENT Il FFICE..

COUNTY OF ANTRIM, IRELAND.

PlsToN.

1 srncrricnrron forming part OrLeaers Patent No.V 292,445, dated January 22, 1884. Application filed September 18, 1853. (No modemy Iatintcd in England February 6,1853, No. G19. l

will enable others skilled in the art to which it appertains to make and use the same.

My invention refers, primarily, to a piston' having two-packing-rings, which are pressed apart from each other and against the junkring and the flange of the body of the piston by an intermediate ring, while the said packing-rings are pressed against the sides of the cylinder by other springs placed on the inside of the said packing-rings. I employ a curved helical spring for pressing the packing-ring apart and outward against the sides of the cylinder, while at the same timeits curved middle portion presses against the `joint-piece or gullet, holding it steam-tight against the inside of the packing-rings. This helical spring is first bent to the required radius and then, at each end, connected to or inserted in abutment pieces or lugs, which are riveted on or otherwise fixed or formed on a thin ring or hoop, made of steel, or iron, and either wave-shaped or plainly circular. This hoop or ring' lies against the inside of the packing-ring, and is nearly of the same depth.

The helical spring may be made from a caststeel tube out in the latheto any pitch required to suit the strength of spring required, or it may be made by winding a ilat, round, or other rod of steel or other suitable elastic material round a mandrel in the ordinary manner. A mandrel or core is placed inside the helical spring to keep it in forni and position when in the piston. The gullet-piece before referred to is preferably made of I -section in the middle.

This description of the improved springs and their action on the packing-rings will be more clearly understood by referring to the.

the same reference-letters areV used inthe several figures to Idenote the saine parts.

Figure l is a plan of a piston, one-half of which is in section, so as to show one of the position, also the hoop or ring C on which the abutments D D are fixed to carry the helical spring B, and receive the pressure therefrom, which pressure is imparted by the hoop to the packing-ring A equally all round its circumference. The joint piece or gullet E, against which the helical spring B presses, is also shown in position in Figures l, 2, and 3. Fig. 2 is a side elevation of the same piston, the right half being in section, showing both packing-rings A A in section, with the flat helical spring B B against the joint-pieces E E. In this section, as well as in sections Figs. 3 and 5, the joint-pieces of both packing-rings are shown together for convenience of illustration, but in practice they break joint with each other in ,the usual manner. In Fig. 3 the helical 'springs B -B are shown of round though'this housing may be confined to the abutment-pieces, as shown on Fig, l. The wave-spring F for pressing the packing-rings endwise yagainst the junk-ring and pistonflange faces is shown in Fig. 2 in elevation on the left-handxhalf of the figure and in section on the right. This spring is also insection in Figs. 3 and 5 in its position between the two packing-rings. In Figs. 2 and 5 the'wavespring-is shown as housed, or lying in a recess in thepacking-ringsmhile in Fig. 3 this spring is shown between the two packing-rings without any housing. The packing-ring may be made in either way without affecting the efciency of the piston.

In cases where a very small space is allowed for the packing-rings, the helical springs may be made to lie close to the packing-rings with only the ring C between. This modification is shown in Figs. 4 and 5, which are, respectively, a part planand sectional elevation. The joint-piece E in this niodiiication does not pro ject beyond the inner diameter of the packingring, and the band which carries the abutpacking-rings A with the helical spring B in vaccompanying sheets of drawings, in which 5o section and partly housed in the gullets E E,

second packing-ring is pnt in, and in this form of piston the wavespring is not, as in Fig. 2, housed between the packing-rings, but lies on the space between them, as shown in Fig. 3.

For gas-niotor engines7 where the pressure acts on vone side only, I may use only one packA ing-ring A, and no spring F.

I claiml. rIhc combination, with a pistou having' packing-rings A, of the inner ring or spring hoop, C, and the helical springs I3, which expand the packing and press the rings A against the sides of the cylinder, substantially as and for'the purpose set'forth.

2. The combination, with a piston having packing-rings A, of the inner ring or springhoop, C, and the helical springs B, which press the packing-rings A against thesides of the cyl index', and the wave-shaped spring F, placed between the packing-rings and serving to press them apart from each other and against the junk-ring or cover and thcpiston-iangc, substantially as and for the purposes set forth.

WILLIAM ROXVAN.

In presence of-- IfRnDK. W. E. WHITE, I. B. Suis 

